Abstract: A propylene block copolymer having good flow properties and a very good low temperature impact strength is obtained in a high yield if a catalyst which consists of a chiral metallocene, containing a bridge, of the formula I ##STR1## and an aluminoxane is used for the polymerization of propylene and the comonomers.The polymerization is carried out in two stages, a crystalline propylene polymer in liquid monomers being prepared in the first stage and a copolymer in the gas phase being prepared in the second stage.

Abstract: A very effective catalyst system for olefin polymerization consists of a cocatalyst, preferably an aluminoxane, and a metallocene of the formula (I) ##STR1## in which, preferably, M.sup.1 is Zr, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 to R.sup.6 are alkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a chain having one or more members, in which R.sup.7 can also be a (substituted) hetero atom, and m+n is zero or 1. The catalyst system leads to polymers of variable molecular weight and stereotacticity, depending on the substituents R.sup.3 to R.sup.6 chosen, at polymerization temperatures which are relevant in industry.

Abstract: The novel metallocenes of the formula I ##STR1## in which, preferably, M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are alkyl or haloalkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a single- or multi-membered chain in which R.sup.7 may also be a (substituted) hetero atom, m+n is zero or 1, and R.sup.10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high stereospecificity and high melting point.

Abstract: The invention relates to a process for the preparation of a compound of the formula XI ##STR1## wherein preferably M.sup.1 is zirconium, the radicals R.sup.1 are alkyl, the radicals R.sup.2 are halogen or alkyl, R.sup.3 is dimethylsilyl or ethylene and n is 2-18, wherein a compound of the formula II ##STR2## is reacted with an alkali metal or alkaline earth metal salt of a malonic ester and then with an alkyl halide, the reaction product is converted by decarboxylation into the corresponding lactone, which is further reacted by known methods to give the compound XI.The compounds of the formula XI, some of which are novel, can advantageously be used as catalysts for olefin polymerization.

Abstract: An immobile (heterogeneous) metallocene catalyst component which can advantageously be used for olefin polymerization is obtained by homopolymerization of appropriately substituted (vinyl group-containing) metallocenes of group IVb of the periodic table or by copolymerization of such metallocenes with (di)vinylaromatic compounds.

Abstract: A very active catalyst system for olefin polymerization is composed of an aluminoxane and a metallocene of the formula I ##STR1## wherein preferably M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are alkyl or haloalkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.m --is a single-membered or multimembered chain in which R.sup.7 may also be a (substituted) hetero atom, and m+n is zero or 1. The catalyst system gives polymers having a high molecular weight and high stereospecificity.

Abstract: A very active catalyst system for olefin polymerization is composed of an aluminoxane and a metallocene of the formula I ##STR1## in which, preferably, M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are alkyl or haloalkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a single-membered or multimembered chain in which R.sup.7 may furthermore be a (substituted) hetero atom, m+n is zero or 1 and R.sup.10 is hydrogen. The catalyst system gives polymers having high stereospecificity and a high melting point.

Abstract: A polypropylene molding composition having syndiotactic polymer chains is obtained in a high yield by the copolymerization of propylene with ethylene or a 1-olefin of the formula R.sup.a --CH.dbd.CH--R.sup.b in the presence of a catalyst comprising a metallocene of the formula I ##STR1## in which M.sup.1 is titanium, zirconium, hafnium, vanadium, riobium or tantalum, and an aluminoxane. This molding composition has a very high molecular weight, a very narrow molecular-weight distribution and very high syndiotaxy. Shaped articles produced from the molding composition are distinguished by high transparency, flexibility, bear strength and excellent surface luster.

Abstract: Olefins of the formulaR.sup.11 --CH.dbd.CH--R.sup.12(R.sup.11 and R.sup.12 =H or C.sub.1 -C.sub.14 -alkyl) are polymerized in the presence of a catalyst comprising at least one metallocene of the formula I ##STR1## (M=zirconium or hafnium) and an aluminoxane, giving polymers of high molecular weight in high yield.

Abstract: The compounds of the formula I or Ia ##STR1## in which R.sup.1 is alkyl, aryl, alkoxy, alkenyl, arylalkyl, alkylaryl, aryloxy, fluoroalkyl, halogenoaryl, alkynyl, trialkylsilyl or a heteroaromatic radical,R.sup.2, R.sup.3 and R.sup.4, in addition to hydrogen, have the meanings given under R.sup.1 andR.sup.5 is hydrogen, alkyl, fluoroalkyl or alkenyl, can be obtained in a one-stage process by reaction of a compound II ##STR2## with (substituted) cyclopentadiene in the presence of a base. The compounds I and Ia are suitable as ligands for metallocene complexes which are used as catalysts in olefin polymerization.

Abstract: An immobile (heterogeneous) metallocene catalyst component which can advantageously be used for olefin polymerization is obtained by homopolymerization of appropriately substituted (vinyl group-containing) metallocenes of group IVb of the periodic table or by copolymerization of such metallocenes with (di)vinyl-aromatic compounds.

Abstract: The novel metallocenes of the formula I ##STR1## in which, preferably, M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are alkyl or haloalkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a single- or multi-membered chain in which R.sup.7 may also be a (substituted) hetero atom, and m+n is zero or 1, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high molecular weight.

Abstract: A syndiotactic polyolefin is obtained in a high yield by polymerization or copolymerization of an olefin of the formula R.sup.a --CH.dbd.CH--R.sup.b in the presence of a catalyst consisting of a metallocene of the formula I ##STR1## and an aluminoxane. This polyolefin has a very high syndiotactic index. At a low polymerization temperature, a polyolefin having a low average molecular weight and narrow molecular weight distribution is obtained, and at a high polymerization temperature a polymer having a high average molecular weight and a wide molecular weight distribution is obtained.Shaped articles produced from the polymers are distinguished by a high transparency, flexibility, tear strength and excellent surface gloss.

Abstract: A chiral, stereorigid metallocene compound of the formula I[R.sup.1 R.sup.2 Si(indenyl)2]Y.sup.2 X (I)(me.sup.2 =Ti, Zr or Hf)which is produced as a virtually pure racemate and can be used as a catalyst component for the polymerization of 1-olefins is obtained by reacting a silylindenyl compound of the formula II[R.sup.1 R.sup.2 Si(indenyl).sub.2 ]Me.sub.2.sup.1 (II)(Me.sup.1 =alkali metal)with a titanium, zirconium or hafnium tetrahalide.

Abstract: Polymers of polycyclic olefins of the formulae I to IV having a viscosity number greater than 20 cm.sup.3 /g and a glass transition temperature above 100.degree. C. are obtained without ring opening at a high polymerization rate and at polymerization temperatures advantageous from the technical point of view by means of a catalyst which is composed of a stereo-rigid, chiral metallocene compound of groups IVb to VIb of the Periodic Table of the Elements and an aluminoxane.

Abstract: The invention relates to a process for the preparation of a predominantly crystalline ethylene/propylene copolymer having less than 15 mol % of propylene units, which can be carried out in liquid propylene as the suspending agent, if metallocene catalyst components of the formulae I, II or III are employed and the partial pressures of ethylene and propylene have a specific ratio. ##STR1## By means of this process, it is possible to increase the possible uses of polymerization plants which work with liquid propylene.

Abstract: Polyolefin waxes are obtained in high yield by copolymerizing propylene with small amounts of other olefins in the presence of a catalyst composed of a metallocene of the formula I: ##STR1## and an alumoxane. The waxes are produced as compact, spherical particles having a narrow particle size distribution and high apparent density. In addition, the physical data of these waxes such as, for example, hardness, melting point, melt viscosity etc., are variable within wide limits.The polymer chains are noteworthy for a homogeneous and uniform structure, the comonomer units being predominantly arranged individually between polypropylene blocks.

Abstract: The invention relates to a process for the preparation of a heterogeneous metallocene catalyst component from a suitably substituted metallocene of the sub-group 4 of the Periodic Table of the Elements and from poly(methylhydrogensiloxane) under the concomitant action of a catalyst. The metallocene component and a suitable aluminoxane can be used as catalyst for the polymerization of 1-olefins, cyclic olefins, diolefins and cyclic diolefins.

Abstract: A bisindenyl derivate of the formula I ##STR1## (M.sup.1 =Si or Ge, R.sup.6 and R.sup.7 =unsubstituted or substituted idenyl radical)is obtained in very good yield by reacting a compound of the formula II ##STR2## (X=halogen) with a compound of the formula III or IVR.sup.6 -M.sup.2 (III) R.sup.7 -M.sup.2 (IV)(M.sup.2 =alkali metal)if, in the reaction, compound III or IV is added slowly to compound II.Compound I is suitable as a starting material for the preparation of metallocene catalyst components.

Abstract: 1-Olefin polymer waxes having a very narrow molecular weight distribution, high isotacticity, a narrow grain size distribution and a high bulk density are obtained by means of a catalyst comprising a chiral, stereorigid metallocene compound and an aluminoxane, in the presence of small amounts of hydrogen during the polymerization.